I think it's just an accident... that and I doubt Komachi's sleeping route even imagined that her husband would be right next to her during that time of day.
And on the side note, I find the fact that the series ended with the family name to be rather fitting. I remember that there are a few anime/manga series that uses the series's name as the title for the last episode/chapter.
glasnost said: So it sounds to me like we may get more stories in the same universe after the omake chapter (i.e. Scarlet Devil's House).
Well, it makes sense, the title of the comic is only referring to the Letty family. What he could do though is after the omake, just decide to choose a more generic sounding title that encompasses his fanon universe.